Lipase Inhibitor
With the recent westernization of life style in Japan, the intake of high-fat meals by the Japanese people is ever increasing. According to the 1999 Japanese national nutrition survey, the energy intake of the Japanese people has been decreasing each year but yet their lipid energy ratio has exceeded the normal levels of about 25%. Also, 50-60% of people aged over 60 have been found to have higher-than-normal neutral fat and cholesterol levels (Ministry of Health, Labor and Welfare, “1999 National Nutrition Survey Results Summarized”, Rinshou Eiyou 2001, 98(5)577-588).
Obesity is one of the most serious conditions in modern society and is mainly ascribed to excessive intake of lipids. Besides obesity, excessive lipid intake is known to cause the onset of associated diseases including diabetes, hyperlipemia, hypertension, and arteriosclerosis. The only drug that has been approved in Japan for treating obesity is the appetite suppressant Mazindol (registered trademark) but Mazindol has been reported to cause side effects such as dry mouth, constipation, discomfort in the stomach, vomiturition or nausea, etc. (Rinsho Hyoka, 1985, 13(2), pp. 419-459; Rinsho Hyoka, 1985, 13(2), pp. 461-515). Outside Japan, Zenical (registered trademark), a drug having sufficient lipase inhibitory activity to suppress intestinal fat absorption, is on the market for treating obesity, but Zenical has also been reported to cause various side effects such as fatty stools, frequent bowel movements, loose passage, diarrhea, stomachache, etc. (Lancet, 1998, 352, pp. 67-172).
Another way that is known to be effective in preventing obesity is to reduce caloric intake through a diet regimen. However, this approach requires strict nutritional guidance and control and, hence, is difficult to implement in everyday life. Therefore, if body absorption of meal-derived fat could be suppressed in a safe and healthy manner, a practical and effective measure could be offered for treating obesity and associated diseases and promoting health.
Under the circumstances, attention is being drawn to the development of “foods for specified health uses” which have been proven to be safe and effective in humans. Foods for specified health uses that have been sold to date as having the ability to suppress the increase of postprandial serum neutral fat levels include a globin digest that suppresses fat absorption by inhibiting pancreatic lipase (J. Nutr. 1988, 128, pp. 56-60; Journal of Nutritional Science and Vitaminology, 1999, 52(2), pp. 71-77; Kenkou•Eiyou Shokuhin Kenkyu, Japan Health Food & Nutrition Food Association, 2002, 5(3), pp. 131-144), diacyl glycerol having different digestion/absorption characteristics compared to triacyl glycerol (J. Am. Coll. Nutr. 2000, 19(6), pp. 789-796; Clin. Chim. Acta. 2001, 11(2), pp. 109-117), and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that are purified from fish oil. In order to suppress the absorption of dietary fat using the foods for specified health uses listed above, it is desirable that they are ingested together with meals. However, it is predicted that the foods listed above may affect the flavor of food and beverage to be taken in with the above-listed foods.
Some polyphenols are known to have activity in inhibiting lipase. Among the examples reported so far are tannin derived from plant bark (JP 60-11912 B), tannins or flavonoids and glycosides thereof that are contained in the leguminous plant Cassia nomame (JP 8-259557 A), lipid absorption suppressing foods having incorporated therein epigallocatechin gallate and epicathechin gallate that are the main components in green tea (JP 3-228664 A), lipase inhibitors comprising water extracts of green pepper, shimeji mushroom, pumpkin, Grifola frondosa, Sargassum fusiforme (Harvey) Setchell, green tea or oolong tea (JP 3-219872 A), flavone and flavonols (JP 7-61927 A), hydroxybenzoic acids (gallic acid) (JP 1-102022 A), triterpene compounds and their derivatives (JP 9-40689 A), and antiobesity drugs containing procyanidin of tamarind as an active ingredient (JP 9-291039 A). Also known are lipase inhibitory action of grape seed extract (Nutrition, 2003, 19, (10), pp. 876-879), the lipase inhibitory action of Salacia oblonga derived polyphenols and their antiobesity action in rat (J. Nutr., 2002, 132, pp. 1819-1824) and the antiobesity action of oolong tea extract in mouse (Int. J. Obes., 1999, 23, pp. 98-105).
The lipid lowering effect of oolong tea has been reported by many researchers. In one report, subjects were allowed to drink commercial oolong tea in 1330 ml portions daily for six weeks to show a significant drop in blood neutral fat levels (Journal of Nutritional Science and Vitaminology, 1991, 44(4), pp. 251-259) and in another, 102 male and female subjects with simple obesity were orally administered oolong tea (2 g×4/day) for six consecutive weeks and a weight loss of at least 1 kg was observed in 67% of the subjects and, in addition, the subjects showing high blood neutral fat levels exhibited significant improvements after ingesting oolong tea (Journal of The Japanese Society of Clinical Nutrition, 1998, 20(1), pp. 83-90).    Non-patent document 1: Ministry of Health, Labor and Welfare, “1999 National Nutrition Survey Results Summarized”, Rinshou Eiyou 2001, 98(5)577-588    Non-patent document 2: Rinsho Hyoka, 1985, 13(2), pp. 419-459    Non-patent document 3: Rinsho Hyoka, 1985, 13(2), pp. 461-515    Non-patent document 4: Lancet, 1998, 352, pp. 67-172    Non-patent document 5: J. Nutr. 1988, 128, pp. 56-60    Non-patent document 6: Journal of Nutritional Science and Vitaminology, 1999, 52(2), pp. 71-77    Non-patent document 7: Kenkou•Eiyou Shokuhin Kenkyu, Japan Health Food & Nutrition Food Association, 2002, 5(3), pp. 131-144    Non-patent document 8: J. Am. Coll. Nutr. 2000, 19(6), pp. 789-796    Non-patent document 9: Clin. Chim. Acta. 2001, 11(2), pp. 876-879    Non-patent document 10: Nutrition, 2003, 19, (10), pp.    Non-patent document 11: J. Nutr., 2002, 132, pp. 1819-1824    Non-patent document 12: Int. J. Obes., 1999, 23, pp. 98-105    Non-patent document 13: Journal of Nutritional Science and Vitaminology, 1991, 44(4), pp. 251-259    Non-patent document 14: Journal of The Japanese Society of Clinical Nutrition, 1998, 20(1), pp. 83-90    Patent document 1: JP 60-11912 B    Patent document 2: JP 8-259557 A    Patent document 3: JP 3-228664 A    Patent document 4: JP 3-219872 A    Patent document 5: JP 7-61927 A    Patent document 6: JP 1-102022 A    Patent document 7: JP 9-40689 A    Patent document 8: JP 9-291039 A